Mold eor making hollow rubber articles



June 29 i926., 1590;?68

Y J. L. MAHON EY MOLD FOR MAKING HOLLOW RUBBER, ARTICLES Filed Dec. 2l,VA19225 5 Sheets-Shee-t 1 INVENTOR, XM 2 BY MMM ATTORNEY June 29 1926.1,590,768

1 .L L.. MAHONEY MOLD FOR MAKING HOLLOW RUBBER ARTICLES Filed Dec. 2l,1923 3 Sheetset 2 www ATroRNEY June 29 19.26o l 1,590,768

gg. L. MAHONEY MOLD FOR MAKING HOLLOW RUBBER ARTICLES Filed Dec. 2l,1925 5 vSheens-Sl'lee'l'l 5 INVENTOR Patented .lune 29,' i926.

ENT FFICE JEREIVIIAI-I L. IVIAIIONEY, OF NEW HAVEN, CONNECTICUT,ASSIGNOR T0 THE CAN- FIELD RUBBER COMPANY, OF BRIDGEPOILT, CONNECTICUT,A CORPORATION OF CONNECTICUT.

MOLD FOR MAKING HOLIIOV RUBBER ARTICLES..

Application filed December 21, 1923. Serial No. 681,905.

My invention relates to improvements in shaping or forming hollow rubberarticles, and also to an improved method of forming such articles. Itwill be understood that in referring to rubber articles, I use the termgenerally as applying to rubber compositions and the like. The object ofmy invention is generallyA to produce hollow rubber articles, such forinstance, as flush tank balls, hollow rubber balls, and other hollowarticles, more cheaply and expeditiously than they are at' present made.In consonance with this idea, my invention also relates to an improvedmold or apparatus which is simple in construction, is thoroughlypractical, and by the use of which I can simultaneously form both partsof a hollow article, such for instance as a ball, then remove the moldportion, and then secure the two parts of the various articles togetherready for the vulcanizing mold. My invention is intended further toprovide a molding apparatus in which the lower part rests on a yieldingbed so as to compensate for any possible inequalities in the moldingapparatus when in use, and in this lower'part I provide a lot ofremovable mold sections. An opposing member which is movable in relationto the first member carries the other mold cavities for the articles tobe formed. Between the two members is a movable plate which carries themold forms to press the rubber sheets into the several cavities, andwhen the movable part of the apparatus is brought to place and theforming members and the stock are in position, a whole series ofarticles are formed at once, and both parts of each article are alsoapproximately shaped. The movable plate is then removed, and anotherstroke of the press, that is another movement of the cavity framestowards each other, secures the two parts of the several articlestogether, and als'o trims the stock around the several articles. I alsoprovide means to insert air under pressure in the formed articles tohold them in shape, and means for relieving the air pressure be hind theparts as they -are formed.

From the description which follows it will be seen that my method andapparatus kprovide a very expeditious simple and sure way of formingarticlesof the kind referred to, and that it operates with no waste oftime or stock.

Figure 1 is a sectional elevation of my improved apparatus showing allthe parts in position for use, and with the stock in position to formthe several articles, the mold members being separated from each other.

Figure 2 is a view similar to Figure 1, but showing the position of theparts when the mold members have been brought towards each other underpressure to form the several articles.

Figure 3 is a view similar to Figure 2 but with the mold carrying platesremoved, and with the press in position to secure the parts of theformed articles together and trim them.

Figure l is a` cross section on the line 4 4 of Figure 2, showingparticularly the arrangement of air ducts.

Figure 5 is a detail of a pair of forming molds.

Figure 6 is a broken sectional inverted plan on the line 6-6 of Figure1.

Figure 7 is a detail section of a formed article before it has beenexpanded in the vulcanizing press, and

Figure 8 is a view of said article when completed.

rlhe apparatus is provided with opposed frames 10 and 11 which are movedback and forth with relation to each other in a manner common to pressesof this kind, and they also have a common means of effecting properregistration, that is to say, the member 10 can be provided with dowelpins 12 adapted to enter corresponding holes 13 in the member 11, sothatthe parts will be properly centered, and instead of this any otherapproved means can be used for eecting proper registration. The frame 10which in the present instance is the lower frame, is preferably mountedon a resilient bed 14 which can conveniently be an elastic composition,held in place by a retaining plate 15. rlhe object of this is to providea yielding support for the part 10, so that when the member 11 is forceddown upon it and the article formed as hereinafter described, anypossible inequalities will be compensated for by the elasticity of thebed. The frame 10 has a series of removable cups 16, each containing acavity 17 lOl to form one part, usually7 one-half of an article, ands asstated, these cups :are preferably removable. They are placed 1ncorresponding cavities of the frame 10, and

ea'ch has a;circumferential edge portion. 18

slightly. raise-d soV to. effect; a: trimming'- of the stock from whichthe articles are formed, as hereinafter described. Each cup has also anopening-through its bottom` or* outer part, a duct 19 connecting with achannel 20, and this With cross outlets 2r so that when the stockisforced inte the cavities oftlie forming cups, the air from the yhackvof thelmold will'y pass outfreely through the duct' l9fandA4 channels20* and. 2T so as to offerno"interferences ivith'theproper formation oi"the article.

The opposite member l1 of the forming.

i' partswliich, in the/present Vinstance 'is 'the theexample V:[haveshovvnin the top or back,

movable trame, has av series of removablevc'ulp`s122iregisteringWith'tlie cups 16', and', having cavitiesthereinto form the op# positel parts of' the articles under manufacture.vIrl-the present instance I haveshown the apparatuses adaptedAv formakingjilush tanlchalls, and` sojthe cavity 23" is. shaped" to form2age-nerally conical top, as. tliis is customary in the trade, but itmight' be any:

other shape,Y as Well. f

@Bviouslythemner surface ot the cavities 1'7" and'QBcan be oli'othershapes,v `and in ofthe cavity 23,- a pinV Q'Llhaving a reduced part 25extendinginto the` Wall of the cavity L haelt, andthe objectief@ thisiste forma-'hole in the top of'thetanl'; hallso that the usual metallicspudl canhe inserted.v Oihvieu-sly the pincouldhe left' outi't itisdesiredftor any reasonto have the: surface off the formed' articlesmooth.

ln.. connection with. the plates. or frames I.O'a,rrclv lljIl use aremovable plate which may, be thinnerand'lighter thanthepartslO andlfl,landfwliich is. adapted'to be usedh'etween them for carrying the formingmolds..

This plate is ageneral'ly dat plate, and. has holes 1.2"? to registerwith th'ehol'es 13 im i f. tliaplateor ramell, so that-the d'ovvel-pinscenter: the plate 26;

ure,.5'). Tliesesect-ions-may be offtl'ie. de -V siredf, shape tof form.the, hollow articles under construction;H As illustratedtlie part. 30 is.intendedV to roughly, mol-d the semispherical@ or4V lower part oa tankhall, while. the part. 31. is intendedM to shapetlie 1 upperA or(generally. conicali part i off a. flush tank ball.,

memloersV and Slarevunited. loyxa screi stud" 28" or similar fastening,and' it Will be noted that they are thus held firmly in. place,and'thattheghaclts of the members 30 and 31: abut With thel plate 26 sothat they are very solid, and When pressure is applied it-'1 comes from`opposite sides:` @tithe mold; members-,a and; ther strain is' taken upby the bodies Yof said membersaandtlregplate 26. The plate 26 is alsorecessed as shown 32^oppes-ite each cup-t6, so that the raised upperedge portionl of each cup may enter the recess 3`2"as shovvn in Figure2, andleave clearance forthe stock-36 under treatment; The plate 26" isalso provided with air ducts 33, these hcingpreferably arranged between"rows of mold cavities asI shownin Figure (iQ- rand airunder pressure mayhe suppliedto the ducts from pipes 34,3

Whichmay iff desired, he flexible.: From thc- 4ducts-33 lranclr ducts 35 deliver to the lowerf` mold.' cavities, and the pressure',y airmay helet into4 tlie several ,cavities to` roughly lliv" out, and expand theformed articles. f

When Vmy. improved`V methodl isytofbe `car-- Vri'ed o.ut,`,the frameslOf and?. Il are'pjlacedu in apress. as usual,v except "that the frame101 is onit'sfresilient. hedlll; sheet otstoclr islaid across-the lowermold cavities IZ' andi cups 1 6',. tlie mol-dlpl'ate '2621 is, insertedVin proper, registry, and cliunls otfruliber 37 eacl-i ha,ving Asu'lcient material" tof form top.. of the, tank.' halls are placed', enthe mol'dmemliersl.assliowneinligurel; i V

stroke. of'l'the press moves the member lil' towardsAtlietmemloer.'llhLandfthe members and 31. off the severa-1 A moldsare.. forced' into] the. corresponding; cavities l? and Q ywhile; the,a1r pressure 1sA let in ,through the. ducts.

and enteringthrough the hranchduc-ts' 35,; forces? the stoclifagainstthe ha-cl otftlie moldsections orA cavities lftliis action he?" ingfacilitated hecause'tle pressure moves out;v from the, hac-k off." the.several' cavities througlilthe` ductsL 19,220 andlQl. ttlie same, momentthe moldmemhers 3l, enter im v ing the: cavities 23, sliape, the. stock,37] to the vshape of the. several. cavities, 'andl :torce the plasticmaterial, around the forming pinsQl; so as totormsped liol'es seel1`'tcggure'y in thei tops o the, several` tanlv halls.It.Willlewnotedtliat attliis iirst stroke of the. press,.tlie hal'r'@members. ofl the several j flush tankballs wil'lzbeformed, thestoch 36tollowing; the contouiu of` the mold cavities andl molds as [shown 1nEigure' 2 an d`f the M,

extendV slightly, beyond theedges ofltliec'avi stock 37 overfiowin-gtliecavities 231er); as to ties.. as. shown in Eigures 2L and'f 4.

Vllerr the members 1l and?4 separate-, the plate A2.6? is removed`, andthe niemliers ofv the pressi again, brought l together as shown inliigure-fy 3, tlie stocl' meanwhile sticking to thei'lachs. offthe,moldlcavities;

Wh'entlie Vplates or frames-l0 land" 11 are brought: together askinFigure, 3.,. the. raised 130 edges 18ct" the cupsA I6"meet thecorresponding parts 22a of the cups 22 as in Figure 3, thereby pressingthe edges of the formed articles together to unite them, and trimmingthe stock around the several formed articles. The raised part 18 of themold sections provides clearance for the waste 26a as shown in Figure 3.The mold plates are then separated, and the articles formed will appearroughly as shown in Figure 7, each tank ball 38 having a generallyconical top 3ia ywith a spud opening 3l' therein and a generallysemi-spherical bottom 36a. These articles are placed in a vulcanizingmold as usual, and chemically or otherwise expanded from the interior togive them their final shape, as shown in Figure 8, as they arevulcanized.

From the drawings and description it will be very clearly seen how awhole series of flush tank balls can be quickly, easily and cheaplyformed by my improved method and apparatus, and it will be evident,obviously that whether the article made is a flush tank ball or otherthing, depends on the shape of the cavities 17 and 9A, and that thesemay be given diHerent shapes to form different things, without in theleast affecting the principle of the invention.

l claim 1. A molding` apparatus comprising opposed frames or platesmovable back and forth with relation to each other and provided withopposed registering mold cavities, and a mold carrier removably arrangedbetween the two plates and having separable molds arranged tosimultaneously enter the cavities of both said frames or plates.

2. A molding apparatus comprising separable plates having opposedregistering mold cavities therein, and a removable member adapted to beplaced between the plates and carrying separable and detachable molds toregister with the aforesaid cavities.

3. A molding apparatus comprising plates or frames movable back andforth with relation to each other and carrying detachable cups havingmold cavities therein, and a removable plate between the said frames,said removable plate carrying separable and detachable mold members toenter the cup cavities.

1. A molding apparatus comprising opposed frames movable with relationto each other and having registering mold cavities therein, a removableplate adapted to be placed between the aforesaid frames, said platehaving mold members to enter the mold cavities of the frames and airducts arranged to discharge into the aforesaid mold cavities.

5. A. molding apparatus comprising opposed frames movable with relationto each other and having registering mold cavities, a removable moldcarrier adapted to be held between the aforesaid frames, said carrierhaving mold members to enter the mold cavities of both frames, an airduct arranged behind the mold cavities to relieve the pressure, and anair duct in the carrier to admit air pressure to the cavities.

6. A molding apparatus comprising opposed frames movable back and forthwith relation to each other and having registering mold cavitiestherein, a removable plate adapted to be arranged between the saidframes, said plate having transverse holes therethrough, and moldmembers having hubs to enter the holes in the plate and adapted to enterthe aforesaid mold cavities.

y7. A molding apparatus comprising opposed frames movable with relationto each other and having registering mold cavities, a removable plateadapted to be arranged between the aforesaid frames, said plate havingtransverse holes therethrough, mold members on opposite sides of theplate to enter the aforesaid mold cavities, and means connecting throughthe aforesaid holes in the plate for uniting the opposed mold members.

8. A molding apparatus comprising opposed frames movable back and forthwith relationto each other and having mold cavities therein, a moldcarrying member having molds to enter the aforesaid cavities, and meansfor relieving air pressure from the backs of the cavities and admittingair pressure to the interior thereof.

9. The herein described method of molding hollow rubber articles, whichconsists in simultaneously molding opposed parts of said articles,admitting air pressure to the molded articles, relieving the airpressure from the backs of said molded articles, then removing themolds, and then uniting and trimming the opposed parts.

In testimony whereof, I have signed my name to this specification this19th day of December, 1923.

JEREMIAH L. MAHONEY.

